Riverine Black Bass/Rock Bass Age and Growth

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[size 1] [/size][#cc9966][font "Comic Sans MS"]In order to address management questions pertaining to the age and growth characteristics of stream dwelling smallmouth bass ([/font][/#cc9966][#cc9966][font "Comic Sans MS"]Micropterus dolomieu[/font][/#cc9966][#cc9966][font "Comic Sans MS"]), spotted bass ([/font][/#cc9966][#cc9966][font "Comic Sans MS"]M. punctulatus[/font][/#cc9966][#cc9966][font "Comic Sans MS"]), largemouth bass ([/font][/#cc9966][#cc9966][font "Comic Sans MS"]M. salmoides[/font][/#cc9966][#cc9966][font "Comic Sans MS"]), and rock bass ([/font][/#cc9966][#cc9966][font "Comic Sans MS"]Ambloplites rupestris[/font][/#cc9966][#cc9966][font "Comic Sans MS"]) populations, collection of otolith samples was initiated in 1995 by each regional TWRA stream survey unit. These efforts represent the first intensive efforts by TWRA to collect this type of data. The focus of the surveys have been primarily on smallmouth bass and rock bass as these two species are the "staple" sport species found in the major river systems of east Tennesee.[/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 1] [/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 1] [/size]Ototliths have been extracted from these species in nine of the major riverine fisheries (Clinch River, Powell River, North Fork Holston River, Nolichucky River, Pigeon River, French Broad River, Holston River, South Fork Holston River, Little Pigeon River) and smaller freestone streams within the region. To date over 3,000 smallmouth bass, spotted bass, largemouth bass, and rock bass have been aged from east Tennessee rivers and streams. Overall, growth of all black bass species and rock bass has been fairly consistent among the rivers and streams within the region. Additionally, the mean length at age values generated from fish in east Tennessee compare quite well with other populations across the state. This indicates black bass and rock bass across the state exhibit similar growth characteristics. The figure below depicts mean lengths at age for black bass and rock bass in nine major river systems of east Tennessee and overall statewide mean length at age for all populations sampled within the state. [/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Specific comparisions of length at age for smallmouth bass among the nine major river systems surveyed thus far, indicate similar growth pattens through age-6. However, it does appear that smallmouth bass in the Nolichucky River and French Broad River generally have a higher mean length at age at least through age-6. Overall, length at age evaluations between the east Tennessee populations and other populations across the U.S. were fairly comparable (see table below). [/size][/font][/#cc9966] [#cc9966][font "Comic Sans MS"][size 2][size 1] [/size]Potential time required to reach 305 mm (12 inches), 356 mm (14 inches), and 406 mm (16 inches) was calculated for smallmouth bass in each of the six large rivers surveyed to date (except North Fork Holston). Based on the analysis, smallmouth bass in the French Broad River required less time to reach the 305 and 356 mm than bass in other rivers. The Clinch and Nolichucky rivers were the same for the 406 mm size class (7.8 years). Overall, bass in the Powell River required more time to reach each respective size class than bass in the other rivers surveyed. The table below depicts the break down of potential time required to reach each size class in six major river systems in east Tennessee. [/size][/font][/#cc9966]
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